1. Field of the Invention
This disclosure generally relates to the design of a semiconductor chip. More specifically, this disclosure relates to a semiconductor chip that serves as a coherence directory and switch chip for a set of processor chips in a multi-chip system.
2. Related Art
The proliferation of the Internet and large data sets has made data centers and clusters of compute servers increasingly common. Such compute servers typically include multiple processor chips that collaborate to provide increased computational capacity for one or more applications. For instance, processor chips in a multi-chip system may be partitioned into multiple, separate domains, where each domain can execute a different instance of an operating system with different applications and/or operate upon a different data set. Higher-level management software typically manages these domains.
As the number of processor chips in a system grows, the number of external communication channels that are available in each processor chip becomes a limitation, and the processor chips are configured to communicate using a separate set of shared communication components. Unfortunately, an error or failure in a shared component that is used by multiple domains can cause all of the domains to fail, thereby affecting the reliability, availability, and serviceability of those domains.
Hence, what is needed are structures and techniques for organizing groups of processor chips into domains without the above-described problems of existing techniques.